The invention relates to a system for confectioning -- by means of capsules -- unitary doses of concentrated products for the extemporary preparation of beverages by means of a pressure fluid, especially a diluent (mostly hot or cold water, gassed water or the like) which is introduced into the capsule and must be delivered from said capsule into the receptacle -- glass, cup or the like -- by means of which the beverage is to be administered.
One object of the invention is that the capsule has a hermetic seal during the preservation before use, even when the capsule contains a liquid dose (for instance, a syrup, a concentrated infusion or the like).
Another object of the invention is that, when the delivery takes place, the mixture, which is formed in the capsule combining the unitary dose and the extemporarily supplied liquid, comes out of the capsule into the administering receptacle, undergoing a filtering effect or at least a pressure drop effect owing to the presence of resistances along the out-flow path; this is required in order to avoid an irregular and violent delivery owing to the fluid pressure which must be attained in the capsule interior to obtain the delivery, said pressure depending upon the supply pressure of the diluent or of a gas delivered simultaneously or subsequently to the diluent. A further object of the invention is that the capsule must ensure the possibility of piercing a sealing baffle to obtain the introduction of the diluent. Still a further object of the invention is that, when the delivery takes place, the contact of the mixture in the capsule with elements of the apparatus used for preparing the beverage is avoided; it is in fact necessary that the same apparatus may be able to deliver from capsules with different contents from one another, without the taste of a previously prepared drink affecting the taste of a subsequently prepared beverage. The capsule may be used in the apparatus according U.S. Pat. No. 3,298,527 to STASSE.